For users having problems downloading/installing psi 2.0: clear out your temporary internet files and your browser cache, and then download the PSI again from this link:- ftp://ftp.secunia.com/PSISetup.exe
Has this resolved the problem?

1. Right click on Start>select Windows Explorer>Navigate to C:\Program Files(x86)\Secunia>click on Secunia to reveal PSI>click PSI - in the right hand pane U will see an uninstall icon>click it & the uninstaller will remove the BETA.

2. Do the same again & U may find it has left behind two LOG FILES>right click on them & select delete.